1. Technical Field
The present invention relates to an oscillation module, an electronic device, and a moving object.
2. Related Art
JP-A-2004-040509 discloses an oscillation circuit including: a differential amplifier for oscillation configured with an ECL line receiver; a differential amplifier for feedback buffering which is configured with an ECL line receiver and in which an output terminal is terminated due to emitter terminating resistance; a switch circuit; a voltage-controlled phase-shift circuit; a SAW resonator having a predetermined resonance frequency; and an impedance circuit, in which a positive feedback oscillation loop is formed with at least the differential amplifier for oscillation, the differential amplifier for feedback buffering, the voltage-controlled phase-shift circuit, and the SAW resonator. According to this oscillation circuit, the emitter terminating resistance of the differential amplifier for feedback buffering is changed to increase a drive level of the SAW resonator, and accordingly, the amplitude of a signal from the SAW resonator is relatively greater than that of the noise superimposed thereon. That is, since a large SN ratio is obtained, it is possible to decrease jitter caused by noise superimposed on the signal from the SAW resonator.
This oscillation circuit outputs an oscillation signal at a frequency (reference frequency) close to a resonance frequency of the SAW resonator, but it is possible to generate a signal at a frequency which is N times the frequency described above by providing a multiplication circuit at a subsequent stage. The oscillation signal output by the multiplication circuit also contains a component of the reference frequency other than a component of the frequency which is N times the frequency described above, but it is possible to reduce the components of the reference frequency by providing a filter circuit at a stage subsequent to the multiplication circuit. In such a case, magnetic field coupling between a coil contained in the oscillation circuit and a coil contained in the filter circuit may be performed to cause degradation of the oscillation signal.